I just replaced the alternator on my Cayman S and there are a few differences from the Boxster article. First, there is absolutely no acces to the alternator from the upper engine access panel - it all has to be done from behind the seats. Second, it's not a simple bolt but a star bolt and you need a particular socket to get both of the alternator bolts off. The longer one butts up against the bulkhead to you really have to finesse the bolt out.